Intersection Syndrome (Oarsman's Wrist)

What happens in intersection syndrome

On the back of the forearm, tendons run through six tunnels (compartments). The first compartment holds two thumb tendons (abductor pollicis longus and extensor pollicis brevis), which cross over the second compartment tendons (the wrist extensors, extensor carpi radialis longus and brevis) a few centimeters above the wrist. Repetitive wrist bending and extending, especially against resistance, causes friction where they cross, leading to inflammation of the tendon sheaths (tenosynovitis), a form of tendinitis.

Symptoms

• forearm pain on the back of the forearm on the thumb side, 4 to 8 cm above the wrist crease
• swelling over that area
• a creaking, squeaking or crunching feeling (crepitus) when moving the wrist, sometimes audible
• pain with gripping, lifting and wrist movement
• tenderness to touch
• in severe cases, redness

Causes and risk factors

• rowing, canoeing and kayaking
• weightlifting, especially curls and cleans
• skiing (planting poles), especially in deep snow
• racquet sports
• raking, shoveling and other repetitive manual tasks
• a sudden increase in training intensity or a change in technique

Intersection syndrome vs De Quervain's tenosynovitis

Other conditions to consider include wrist sprains, carpal tunnel syndrome (numbness in the fingers rather than forearm pain), and radial nerve irritation.

Diagnosis

Diagnosis is usually made by examination: pinpoint tenderness, swelling and crepitus at the crossing point. If the picture is unclear:

• ultrasound shows fluid and thickening around the tendons
• MRI shows inflammation at the intersection
• X-rays are usually normal

Treatment

First steps

• rest: stop or reduce the aggravating activity for 2 to 3 weeks
• splint: a thumb spica splint holding the wrist slightly extended (about 15 degrees) rests both tendon groups
• ice: 15 to 20 minutes several times a day
• pain relief: NSAIDs such as ibuprofen or naproxen, following the label dose; avoid if you have kidney problems or stomach ulcers

Most people improve within 2 to 3 weeks.

If symptoms persist

• steroid injection into the tendon sheath at the intersection
• physical or hand therapy for gradual strengthening and technique correction
• surgery to release and clean the tendon sheaths is rarely needed

Returning to sport

Return gradually once pain-free, increasing load over a few weeks. Check technique: rowers often benefit from adjusting wrist position during the "feather"; lifters may change grip or reduce volume.

Prevention

• increase training volume gradually
• use correct technique and equipment
• take breaks during repetitive tasks
• strengthen forearm muscles

Frequently asked questions

What is intersection syndrome?

Intersection syndrome is inflammation of forearm tendons where two groups of thumb and wrist tendons cross, a few centimeters above the wrist on the back of the forearm. It causes pain, swelling and often a creaking feeling with wrist movement, usually from repetitive use.

How is intersection syndrome different from De Quervain's?

Intersection syndrome hurts higher up the forearm, 4 to 8 cm above the wrist, and often creaks. De Quervain's tenosynovitis hurts right at the wrist over the bony bump on the thumb side, typically with pinching and gripping.

How long does intersection syndrome take to heal?

With rest, a splint and anti-inflammatories, most cases improve within 2 to 3 weeks. Returning to the aggravating activity too early can cause a relapse. Persistent cases may need a steroid injection.

Why does my forearm squeak when I move my wrist?

A squeaking or creaking feeling on the back of the forearm usually means inflamed tendon sheaths rubbing together, as in intersection syndrome. It is common after unaccustomed rowing, lifting or raking and settles with rest.